Werdenberg was a county of the Holy Roman Empire

Holy Roman Empire

The Holy Roman Empire was a realm that existed from 962 to 1806 in Central Europe.It was ruled by the Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes...

 situated on either side of the Rhine, including parts of what is now St. Gallen

Canton of St. Gallen

The Canton of St. Gallen is a canton of Switzerland. St. Gallen is located in the north east of Switzerland. It covers an area of 2,026 km², and has a population of . , the population included 97,461 foreigners, or about 20.9% of the total population. The capital is St. Gallen. Spelling...

 (Switzerland

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

), Liechtenstein

Liechtenstein

The Principality of Liechtenstein is a doubly landlocked alpine country in Central Europe, bordered by Switzerland to the west and south and by Austria to the east. Its area is just over , and it has an estimated population of 35,000. Its capital is Vaduz. The biggest town is Schaan...

, and Vorarlberg

Vorarlberg

Vorarlberg is the westernmost federal-state of Austria. Although it is the second smallest in terms of area and population , it borders three countries: Germany , Switzerland and Liechtenstein...

 (Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

).
It is named for Werdenberg Castle

Werdenberg Castle

Werdenberg Castle is a castle in the municipality of Grabs of the Canton of St. Gallen in Switzerland. It is a Swiss heritage site of national significance.-References:...

, today located in the municipality of Grabs

Grabs

Grabs is a municipality in the Wahlkreis of Werdenberg in the canton of St. Gallen in Switzerland.-History:Grabs is first mentioned in 841 as Quaravedes. In 979 it was mentioned as Quadravedes, then in 1235 as Grabdis and in 1253 as Graps.-Geography:Grabs has an area, , of...

 in the Swiss canton of St. Gallen.
It was partitioned from Montfort in 1230. In 1260, it was divided into Werdenberg and Sargans

County of Sargans

The County of Sargans was a state of the Holy Roman Empire. From 1458 until the French Revolutionary War in 1798, Sargans became a condominium of the Old Swiss Confederacy, administered jointly by the cantons of Uri, Schwyz, Unterwalden, Lucerne, Zürich, Glarus and Zug.-History:In 1396, the counts...

,
in 1308 Werdenberg was further divided into Werdenberg-Heiligenberg and Werdenberg-Werdenberg. The Vaduz

Vaduz

Vaduz is the capital of the principality of Liechtenstein and the seat of the national parliament. The town, located along the Rhine, has about 5,100 inhabitants , most of whom are Roman Catholic. Its cathedral is the seat of a Roman Catholic archbishop....

 line of Counts of Werdenberg died out in 1406 and Vaduz passed to the Barons of Brandis.